Analysis of Systemic Epigenetic Alterations in Inflammatory Bowel Disease: Defining Geographical, Genetic and Immune-Inflammatory influences on the Circulating Methylome

BACKGROUND

Epigenetic alterations may provide valuable insights into gene-environment interactions in the pathogenesis of inflammatory bowel disease [IBD].

METHODS

Genome-wide methylation was measured from peripheral blood using the Illumina 450k platform in a case-control study in an inception cohort (295 controls, 154 Crohn's disease [CD], 161 ulcerative colitis [UC], 28 IBD unclassified [IBD-U)] with covariates of age, sex and cell counts, deconvoluted by the Houseman method. Genotyping was performed using Illumina HumanOmniExpressExome-8 BeadChips and gene expression using the Ion AmpliSeq Human Gene Expression Core Panel. Treatment escalation was characterized by the need for biological agents or surgery after initial disease remission.

RESULTS

A total of 137 differentially methylated positions [DMPs] were identified in IBD, including VMP1/MIR21 [p = 9.11 × 10-15] and RPS6KA2 [6.43 × 10-13], with consistency seen across Scandinavia and the UK. Dysregulated loci demonstrate strong genetic influence, notably VMP1 [p = 1.53 × 10-15]. Age acceleration is seen in IBD [coefficient 0.94, p < 2.2 × 10-16]. Several immuno-active genes demonstrated highly significant correlations between methylation and gene expression in IBD, in particular OSM: IBD r = -0.32, p = 3.64 × 10-7 vs non-IBD r = -0.14, p = 0.77]. Multi-omic integration of the methylome, genome and transcriptome also implicated specific pathways that associate with immune activation, response and regulation at disease inception. At follow-up, a signature of three DMPs [TAP1, TESPA1, RPTOR] were associated with treatment escalation to biological agents or surgery (hazard ratio of 5.19 [CI: 2.14-12.56], logrank p = 9.70 × 10-4).

CONCLUSION

These data demonstrate consistent epigenetic alterations at diagnosis in European patients with IBD, providing insights into the pathogenetic importance and translational potential of epigenetic mapping in complex disease.

Characterisation of the Circulating Transcriptomic Landscape in Inflammatory Bowel Disease Provides Evidence for Dysregulation of Multiple Transcription Factors Including NFE2, SPI1, CEBPB, and IRF2

AIM

To assess the pathobiological and translational importance of whole-blood transcriptomic analysis in inflammatory bowel disease [IBD].

METHODS

We analysed whole-blood expression profiles from paired-end sequencing in a discovery cohort of 590 Europeans recruited across six countries in the IBD Character initiative (newly diagnosed patients with Crohn's disease [CD; n = 156], ulcerative colitis [UC; n = 167], and controls [n = 267]), exploring differential expression [DESeq2], co-expression networks [WGCNA], and transcription factor involvement [EPEE, ChEA, DoRothEA]. Findings were validated by analysis of an independent replication cohort [99 CD, 100 UC, 95 controls]. In the discovery cohort, we also defined baseline expression correlates of future treatment escalation using cross-validated elastic-net and random forest modelling, along with a pragmatic ratio detection procedure.

RESULTS

Disease-specific transcriptomes were defined in IBD [8697 transcripts], CD [7152], and UC [8521], with the most highly significant changes in single genes, including CD177 (log2-fold change [LFC] = 4.63, p = 4.05 × 10-118), MCEMP1 [LFC = 2.45, p = 7.37 × 10-109], and S100A12 [LFC = 2.31, p = 2.15 × 10-93]. Significantly over-represented pathways included IL-1 [p = 1.58 × 10-11], IL-4, and IL-13 [p = 8.96 × 10-9]. Highly concordant results were obtained using multiple regulatory activity inference tools applied to the discovery and replication cohorts. These analyses demonstrated central roles in IBD for the transcription factors NFE2, SPI1 [PU.1], CEBPB, and IRF2, all regulators of cytokine signalling, based on a consistent signal across cohorts and transcription factor ranking methods. A number of simple transcriptome-based models were associated with the need for treatment escalation, including the binary CLEC5A/CDH2 expression ratio in UC (hazard ratio = 23.4, 95% confidence interval [CI] 5.3-102.0).

CONCLUSIONS

Transcriptomic analysis has allowed for a detailed characterisation of IBD pathobiology, with important potential translational implications.

Mucosal Gene Transcript Signatures in Treatment Naïve Inflammatory Bowel Disease: A Comparative Analysis of Disease to Symptomatic and Healthy Controls in the European IBD-Character Cohort

Background

Studies of the mucosal transcriptomic landscape have given new insight into the pathogenesis of inflammatory bowel disease (IBD). Recently, the predictive biomarker potential of gene expression signatures has been explored. To further investigate the mucosal gene expression in IBD, we recruited a cohort of treatment naïve patients and compared them to both symptomatic and healthy controls.

Methods

Altogether, 323 subjects were included: Crohn’s disease (N = 75), ulcerative colitis (N = 87) and IBD unclassified (N = 3). Additionally, there were two control groups: symptomatic controls (N = 131) and healthy controls (N = 27). Mucosal biopsies were collected during ileocolonoscopy and gene expression in inflamed and non-inflamed mucosa was explored. Gene expression profiling was performed using Agilent G3 Human Gene Expression 860K v3 One-Color microarray. We recorded information about treatment escalation to anti-TNF agents or surgery, and anti-TNF response, to explore predictive opportunities of the mucosal transcriptome.

Results

Gene expression profiles in symptomatic controls in whom IBD had been excluded resembled that of IBD patients and diverged from that of healthy controls. In non-inflamed Crohn’s disease and ulcerative colitis, gene set enrichment analysis revealed dysregulation of pathways involved in basic cellular biological processes. Mitochondria-associated pathways were dysregulated both in non-inflamed and inflamed Crohn’s disease and ulcerative colitis (>2.6 normalized enrichment scores <−1.8). Gene expression signatures of Crohn’s disease and ulcerative colitis did not predict time for treatment escalation (p = 0.175). No significant association was found between gene expression signatures and anti-TNF response.

Conclusion

Non-inflamed samples are probably superior to inflamed samples when exploring gene expression signatures in IBD and might reveal underlying mechanisms central for disease initiation. The gene expression signatures of the control groups were related to if they were symptomatic or not, which may have important implications for future study designs.

Serum proteomic profiling at diagnosis predicts clinical course, and need for intensification of treatment in inflammatory bowel disease

BACKGROUND

Success in personalized medicine in complex disease is critically dependent on biomarker discovery. We profiled serum proteins using a novel proximity extension assay [PEA] to identify diagnostic and prognostic biomarkers in inflammatory bowel disease [IBD].

METHODS

We conducted a prospective case-control study in an inception cohort of 552 patients [328 IBD, 224 non-IBD], profiling proteins recruited across six centres. Treatment escalation was characterized by the need for biological agents or surgery after initial disease remission. Nested leave-one-out cross-validation was used to examine the performance of diagnostic and prognostic proteins.

RESULTS

A total of 66 serum proteins differentiated IBD from symptomatic non-IBD controls, including matrix metallopeptidase-12 [MMP-12; Holm-adjusted p = 4.1 × 10-23] and oncostatin-M [OSM; p = 3.7 × 10-16]. Nine of these proteins are associated with cis-germline variation [59 independent single nucleotide polymorphisms]. Fifteen proteins, all members of tumour necrosis factor-independent pathways including interleukin-1 (IL-1) and OSM, predicted escalation, over a median follow-up of 518 [interquartile range 224-756] days. Nested cross-validation of the entire data set allowed characterization of five-protein models [96% comprising five core proteins ITGAV, EpCAM, IL18, SLAMF7 and IL8], which define a high-risk subgroup in IBD [hazard ratio 3.90, confidence interval: 2.43-6.26], or allowed distinct two- and three-protein models for ulcerative colitis and Crohn's disease respectively.

CONCLUSION

We have characterized a simple oligo-protein panel that has the potential to identify IBD from symptomatic controls and to predict future disease course. Further prospective work is required to validate our findings.

Whole Blood Profiling of T-cell-Derived microRNA Allows the Development of Prognostic models in Inflammatory Bowel Disease

BACKGROUND

MicroRNAs [miRNAs] are cell-specific small non-coding RNAs that can regulate gene expression and have been implicated in inflammatory bowel disease [IBD] pathogenesis. Here we define the cell-specific miRNA profiles and investigate its biomarker potential in IBD.

METHODS

In a two-stage prospective multi-centre case control study, next generation sequencing was performed on a discovery cohort of immunomagnetically separated leukocytes from 32 patients (nine Crohn's disease [CD], 14 ulcerative colitis [UC], eight healthy controls) and differentially expressed signals were validated in whole blood in 294 patients [97 UC, 98 CD, 98 non-IBD, 1 IBDU] using quantitative PCR. Correlations were analysed with phenotype, including need for early treatment escalation as a marker of progressive disease using Cox proportional hazards.

RESULTS

In stage 1, each leukocyte subset [CD4+ and CD8+ T-cells and CD14+ monocytes] was analysed in IBD and controls. Three specific miRNAs differentiated IBD from controls in CD4+ T-cells, including miR-1307-3p [p = 0.01], miR-3615 [p = 0.02] and miR-4792 [p = 0.01]. In the extension cohort, in stage 2, miR-1307-3p was able to predict disease progression in IBD (hazard ratio [HR] 1.98, interquartile range [IQR]: 1.20-3.27; logrank p = 1.80 × 10-3), in particular CD [HR 2.81; IQR: 1.11-3.53, p = 6.50 × 10-4]. Using blood-based multimarker miRNA models, the estimated chance of escalation in CD was 83% if two or more criteria were met and 90% for UC if three or more criteria are met.

INTERPRETATION

We have identified and validated unique CD4+ T-cell miRNAs that are differentially regulated in IBD. These miRNAs may be able to predict treatment escalation and have the potential for clinical translation; further prospective evaluation is now indicated.

Faecal microbiota signatures of IBD and their relation to diagnosis, disease phenotype, inflammation, treatment escalation and anti-TNF response in a European Multicentre Study (IBD-Character)

METHOD

We examined faecal samples, using the GA-map™ Dysbiosis Test, to associate gut microbiota composition with Crohn's disease (CD) and ulcerative colitis (UC) and to identify markers for future biomarker identification. We conducted a prospective case-control study (EU-ref. no. 305676) in an inception cohort of 324 individuals (64 CD, 84 UC, 116 symptomatic non-IBD controls and 44 healthy controls) across five European centres and examined 54 predetermined bacterial markers. We categorized patients according to the Montreal Classification and calculated the dysbiosis index (DI). Non-parametric tests were used to compare groups and the Bonferroni correction to adjust for multiple comparisons.

RESULTS

The fluorescent signals (FSSs) for Firmicutes and Eubacterium hallii were lower in inflammatory bowel disease (IBD) vs. symptomatic controls (p<.05). FSS for Firmicutes, Lachnospiraceae, Eubacterium hallii and Ruminococcus albus/bromii were lower, whereas the signal for Bacteroides Fragilis was higher in UC vs. symptomatic controls (p<.05). FSS was higher for Bifidobacterium spp., Eubacterium hallii, Actinobacteria and Firmicutes among patients with ulcerative proctitis, compared to extensive colitis (p<.05). In CD, we observed no association with disease location. The DI correlated with faecal-calprotectin in both CD and in UC (p<.001). In terms of treatment escalation and anti-TNF response, differences were observed for some bacterial markers, but none of these associations were statistically significant.

CONCLUSION

Our data reveal that the GA-map™ Dysbiosis Test holds the potential to characterize the faecal microbiota composition and to assess the degree of dysbiosis in new-onset IBD. On the other hand, our results cannot demonstrate any proven diagnostic or predictive value of this method to support clinical decision making.

Serological antibodies and surgery in a population-based inception cohort of Crohn's disease patients - the IBSEN study

Introduction: Serological antibodies have been associated with complicated disease course in Crohn's disease (CD), including the need for surgery.Aim: The aim of this study was to investigate if a panel of relevant antibodies could predict surgery in a prospective population-based cohort of patients with CD.Methods: The population-based IBSEN cohort has been followed prospectively for 20 years. At the 10- and 20-year follow-up, the following panel of serological antibodies was analysed: pANCA, ASCA IgA, ASCA IgG, anti-OmpC, anti-I2, and anti-CBir1. At the 20-year follow-up or until lost to follow-up, all CD-related surgeries were registered.Results: Serum was available from 159 patients at 10-year follow-up and 135 patients at 20-year follow-up. In 113 patients, serum was available at both time points. No significant change of antibody status (positive vs. negative) was found from 10-year to 20-year follow-up. Negative pANCA, positive ASCA IgA and positive ASCA IgG at 10-year follow-up were all individually associated with increased risk for CD-related surgery. There was no association between anti-OmpC, anti-I2 or anti-CBir1 and CD-related surgery. In a multiple regression model including disease location and behaviour, only stricturing or penetrating disease behaviour and negative pANCA remained significantly associated with higher odds for surgery.Conclusion: Positive ASCA IgA and IgG, and negative pANCA were associated with higher odds for CD-related surgery in univariate analysis. Since disease phenotype changes during the disease course, while serological antibodies are stable, our results support the use of pANCA, ASCA IgA and ASCA IgG as prognostic markers in CD.

Risk of colorectal cancer in a population-based study 20 years after diagnosis of ulcerative colitis: results from the IBSEN study

Objective

The association between ulcerative colitis (UC) and colorectal cancer (CRC) is widely accepted, although attenuated risk has been reported in recent years. Colonoscopic surveillance is recommended with intervals based on established clinical risk factors. Nevertheless, a significant number of patients develop interval cancers, indicating the need of improved individualised assessment. In the present study, we evaluated clinical risk factors associated with CRC during a prescheduled follow-up 20 years after diagnosis, the IBSEN study.

Design

A population-based inception cohort of patients diagnosed with inflammatory bowel disease from 1 January 1990 until 31 December 1993, prospectively followed at 1, 5, 10 and 20 years after diagnosis. A total of 517 patients with UC were included; 264 (51 %) men; median age at inclusion 37.4 years (4–88).

Results

The overall incidence of CRC was 1.6% (8/517) at a 20-year follow-up. The total lifetime risk of CRC prior to or after UC diagnosis was 2.3%. (12/517). Patients older than 70 years at diagnosis had a 15-fold higher risk of CRC compared with those diagnosed when younger than 40 years, with HR 15.68 (95% CI: 1.31 to 187.92). Neither sex, first-degree relative with CRC, extent of colitis nor primary sclerosing cholangitis affected the risk of CRC.

Conclusion

The risk of CRC in UC was low and comparable with the risk of CRC in the background population of Norway.

Intake of dairy protein during pregnancy in IBD and risk of SGA in a Norwegian population-based mother and child cohort

BACKGROUND

Patients with inflammatory bowel disease (IBD) tend to avoid dairy products to minimize abdominal pain and diarrhea. The aim of this study was to estimate the proportion of protein from dairy sources (PPDS) in mothers with and without IBD, and to explore the impact of PPDS on inadequate gestational weight gain (GWG) or small for gestational age (SGA) in IBD compared to non-IBD in the population-based Norwegian Mother, Father and Child Cohort Study (MoBa).

METHODS

MoBa includes about 95,000 pregnant women recruited throughout Norway from 1999 to 2008. IBD phenotype and complications during pregnancy and delivery were ascertained. This study included 148 mothers with Crohn disease (CD) and 194 with ulcerative colitis and 68,858 non-IBD mothers. In mid-pregnancy participants answered a comprehensive semi-quantitative food frequency questionnaire assessing diet since the start of pregnancy. PPDS was ranked in quartiles. The two lowest quartiles were merged and considered to represent the lowest of three PPDS groups. We used logistic regression analyses to model multivariate associations, adjusting for potential confounders.

RESULTS

The risk of belonging to the lowest PPDS group was twice as high in IBD mothers compared to non-IBD mothers (aOR = 2.02, 95% CI: 1.53, 2.67). Low compared to high PPDS strongly predicted inadequate GWG in CD (aOR = 4.22, 95% CI: 1.28, 13.92). Surprisingly, and in opposition to the non-IBD mothers, PPDS was positively associated with the risk of SGA in IBD mothers. IBD mother with low PPDS was associated with significantly lower risk of SGA than non-IBD mothers and IBD mothers with high PPDS (aOR = 0.19, 95% CI: 0.07, 0.50). The interaction term IBD/PPDS was the factor that linked SGA to IBD compared to non-IBD, and increased the association between IBD and SGA with a factor of three.

CONCLUSION

This study shows that intake of dairy products is lower in IBD mothers than in non-IBD mothers, and further, that low intake of dairy products in IBD mothers is associated with reduced risk of SGA compared to non-IBD and IBD mothers with high PPDS.

Genetic and transcriptional analysis of inflammatory bowel disease-associated pathways in patients with GUCY2C-linked familial diarrhea

OBJECTIVE

Activating mutations in the GUCY2C gene, which encodes the epithelial receptor guanylate cyclase C, cause diarrhea due to increased loss of sodium chloride to the intestinal lumen. Patients with familial GUCY2C diarrhea syndrome (FGDS) are predisposed to inflammatory bowel disease (IBD). We investigated whether genes in the guanylate cyclase C pathway are enriched for association with IBD and reversely whether genetic or transcriptional changes associated with IBD are found in FGDS patients.

METHODS

(1) A set of 27 genes from the guanylate cyclase C pathway was tested for enrichment of association with IBD by Gene Set Enrichment Analysis, using genome-wide association summary statistics from 12,882 IBD patients and 21,770 controls. (2) We genotyped 163 known IBD risk loci and sequenced NOD2 in 22 patients with FGDS. Eight of them had concomitant Crohn's disease. (3) Global gene expression analysis was performed in ileal tissue from patients with FGDS, Crohn's disease and healthy individuals.

RESULTS

The guanylate cyclase C gene set showed a significant enrichment of association in IBD genome-wide association data. Risk variants in NOD2 were found in 7/8 FGDS patients with concomitant Crohn's disease and in 2/14 FDGS patients without Crohn's disease. In ileal tissue, downregulation of metallothioneins characterized FGDS patients compared to healthy controls.

CONCLUSIONS

Our results support a role of guanylate cyclase C signaling and disturbed electrolyte homeostasis in development of IBD. Furthermore, downregulation of metallothioneins in the ileal mucosa of FGDS patients may contribute to IBD development, possibly alongside effects from NOD2 risk variants.

The prevalence and transcriptional activity of the mucosal microbiota of ulcerative colitis patients

Active microbes likely have larger impact on gut health status compared to inactive or dormant microbes. We investigate the composition of active and total mucosal microbiota of treatment-naïve ulcerative colitis (UC) patients to determine the microbial picture at the start-up phase of disease, using both a 16S rRNA transcript and gene amplicon sequencing. DNA and RNA were isolated from the same mucosal colonic biopsies. Our aim was to identify active microbial members of the microbiota in early stages of disease and reveal which members are present, but do not act as major players. We demonstrated differences in active and total microbiota of UC patients when comparing inflamed to non-inflamed tissue. Several taxa, among them the Proteobacteria phyla and families therein, revealed lower transcriptional activity despite a high presence. The Bifidobacteriaceae family of the Actinobacteria phylum showed lower abundance in the active microbiota, although no difference in presence was detected. The most abundant microbiota members of the inflamed tissue in UC patients were not the most active. Knowledge of active members of microbiota in UC patients could enhance our understanding of disease etiology. The active microbial community composition did not deviate from the total when comparing UC patients to non-IBD controls.

Multi-target stool DNA test in the surveillance of inflammatory bowel disease: a cross-sectional cohort study

BACKGROUND AND AIM

Colonoscopic surveillance is recommended in patients with longstanding inflammatory bowel disease (IBD) as they are at increased risk of colorectal cancer (CRC). Non-invasive surveillance may improve compliance and access. Multi-target stool DNA (MT-sDNA) has been validated for screening of sporadic CRC but has not been assessed in IBD. Our aim was to assess the performance of a MT-sDNA test in a real-life surveillance setting of patients with longstanding IBD.

MATERIAL AND METHODS

A total of 192 IBD patients enrolled from two prospective cohorts submitted an EDTA buffered stool sample and underwent chromo- or white light colonoscopy. Stools were assayed for methylated BMP3 & NDRG4, mutant KRAS and β-actin by a laboratory blinded to clinical data.

RESULTS

The multitarget-sDNA panel was positive in 2/2 CRC and 5/15 low-grade dysplasia (LGD) < 1 cm in diameter. Sensitivities were 100% (95% CI 16-100%) for CRC and 33% (95% CI 13-61%) for LGD lesions <1 cm, with specificities of 87% (95% CI 81-91%) and 93% (95% CI 88-96%), respectively. The estimated number of patients needed to screen to detect a single CRC was 96 (95% CI 93-99%) and was 28 (95% CI 22-34%) to detect any colorectal neoplasia (CRN).

CONCLUSION

The MT-sDNA panel detected CRC in IBD. Sensitivity for sub-centimeter colorectal neoplasms in IBD patients appears similar to that observed in the general population. The test may be a valuable tool for detection of malignancy during structured surveillance of long-term IBD in a first line hospital setting.

Dietary Patterns in women with Inflammatory Bowel Disease and Risk of Adverse Pregnancy Outcomes: Results from The Norwegian Mother and Child Cohort Study (MoBa)

BACKGROUND

The aim of the study was to examine dietary patterns and risk of adverse pregnancy outcomes among mothers with inflammatory bowel disease (IBD) in the Norwegian Mother and Child Cohort Study (MoBa).

METHOD

MoBa enrolled participants from all over Norway between 1999 and 2008, and the study comprised 83,988 mothers, of whom there were 183 mothers with Crohn's disease (CD) and 240 with ulcerative colitis (UC). An additional questionnaire was submitted to mothers with IBD in 2013. We extracted three exploratory dietary patterns: a "Prudent," a "Western," and a "Traditional" pattern. We explored the relationship between dietary patterns and IBD and dietary patterns and adverse pregnancy outcomes: small for gestational age (SGA) and preterm delivery (PTD).

RESULTS

IBD mothers had a significantly lower adherence to the Traditional dietary pattern [mean score -0.10 (95% CI: - 0.2 - - 0.01)] than non-IBD mothers. In IBD mothers, middle and high adherence to the Traditional dietary pattern was associated with lower risk of SGA [OR tertile 2 vs. tertile 1: 0.44 (95% CI: 0.20 - 0.97) and OR tertile 3 vs. tertile 1: 0.23 (95% CI: 0.08-0.61)] than in IBD and non-IBD mothers with low adherence. In the IBD-subset analyses, similar results were demonstrated for UC mothers [OR tertile 2 vs. tertile 1: 0.21 (95% CI: 0.05 - 0.80) and OR tertile 3 vs. tertile 1: 0.16 (95% CI: 0.04 - 0.60)].

CONCLUSION

In IBD mothers, higher adherence to a Traditional dietary pattern, characterized by high consumption of lean fish, fish products, potatoes, rice porridge, cooked vegetables, and gravy, was associated with lower risk of SGA.

Inadequate Gestational Weight Gain Predicts Adverse Pregnancy Outcomes in Mothers with Inflammatory Bowel Disease: Results from a Prospective US Pregnancy Cohort

BACKGROUND

Malnutrition and weight loss are common features of patients with inflammatory bowel disease (IBD).

AIM

To explore the impact of inadequate gestational weight gain (GWG) on adverse outcomes among IBD mothers in the prospective US pregnancy in Inflammatory Bowel Disease and Neonatal Outcomes (PIANO) cohort.

METHODS

The PIANO cohort comprises 559 and 363 pregnant mothers with Crohn's disease (CD) and ulcerative colitis (UC), respectively, enrolled between 2006 and 2014. The mothers were followed during and after pregnancy to ascertain medication, measurement of disease activity and complications during pregnancy and at delivery. Inadequate GWG was based on US Institute of Medicine recommendations. The associations between inadequate GWG and adverse pregnancy outcomes in maternal IBD were analyzed, adjusted for diabetes, hypertension, smoking, maternal age, education, and disease activity.

RESULTS

Maternal CD and UC with inadequate GWG had a 2.5-fold increased risk of preterm birth (OR 2.5, CI 1.3, 4.9 and OR 2.5, CI 1.2, 5.6). Furthermore, an increased risk of intrauterine growth restriction and a trend for small for gestational age were demonstrated in CD but not in UC (OR 3.3, CI 1.1, 10.0, OR 4.5, CI 0.8, 24.3, p = 0.08). Flares increased risk of inadequate GWG (OR 1.6, CI 1.2, 2.3, p = 0.002) but did not change the associations between inadequate GWG and adverse pregnancy outcomes in our models.

CONCLUSION

The US PIANO cohort demonstrated that inadequate GWG was a strong independent predictor of adverse pregnancy outcomes in IBD mothers.

Antineutrophil antibodies define clinical and genetic subgroups in primary sclerosing cholangitis

BACKGROUND & AIMS

The strongest genetic risk factors in primary sclerosing cholangitis (PSC) are encoded in the HLA complex. Antineutrophil cytoplasmic antibodies (ANCA) have been reported in up to 94% of PSC patients, but their clinical significance and immunogenetic basis are ill defined. We aimed to characterize clinical and genetic associations of ANCA in PSC.

METHODS

Antineutrophil cytoplasmic antibodies were analysed with indirect immunofluorescence in 241 Norwegian PSC patients. HLA-B and HLA-DRB1 genotyping was performed in the patients and in 368 healthy controls. Data on perinuclear ANCA (pANCA) and HLA-DRB1 were available from 274 ulcerative colitis (UC) patients without known liver disease.

RESULTS

Antineutrophil cytoplasmic antibodies were found in 193 (80%) of the PSC patients, with pANCA in 169 (70%). ANCA-positive patients were younger than ANCA negative at diagnosis of PSC and had a lower frequency of biliary cancer (9% vs 19%, P=.047). There were no differences between PSC patients with and without inflammatory bowel disease. Genetically, the strong PSC risk factors HLA-B*08 (frequency in healthy 13%) and DRB1*03 (14%) were more prevalent in ANCA-positive than -negative patients (43% vs 25%, P=.0012 and 43% vs 25%, P=.0015 respectively). The results were similar when restricting the analysis to pANCA-positive patients. In UC patients without liver disease, HLA-DRB1*03 was more prevalent in pANCA-positive compared with -negative patients (P=.03).

CONCLUSIONS

Antineutrophil cytoplasmic antibodies identified PSC patients with particular clinical and genetic characteristics, suggesting that ANCA may mark a clinically relevant pathogenetic subgroup in the PSC-UC disease spectrum.

Inflammatory bowel disease

Scandinavian researchers have contributed to the present understanding of inflammatory bowel disease (IBD). Important epidemiological data and family risk factors have been reported from all the Nordic countries, original twin studies mainly from Denmark and Sweden, and relationships to cancer and surgery mostly from Sweden. In collaboration with the industry, development of medical compounds was for a long time in the front line of international research, and the Scandinavian countries participated in the clinical breakthrough of biologic treatment. At present, many Nordic centers are working in the forefront of IBD research. An increasing number of young investigators have entered the scene along with the extended distribution of University clinics and research laboratories in these countries. This presentation of IBD gives a brief overview in the fields of clinical epidemiology and molecular biology. Many areas are covered by International collaborations with partners from Nordic centers. IBD was a topic focused by the founders of Scandinavian Journal of Gastroenterology. After 50 years one may state that the journal's history reflects important pieces of scientific knowledge within these diseases. The early scope of Johannes Myren for IBD was shown through his work in the original World Association of Gastroenterology (OMG), and after 50 years we can clearly support the view that global perspectives in IBD are increasingly important.

Co-occurrence of IBS and symptoms of anxiety or depression, among Norwegian twins, is influenced by both heredity and intrauterine growth

Background

Environmental and genetic factors contribute to variation in irritable bowel syndrome (IBS), anxiety and depression. Comorbidity between these disorders is high. A previous investigation of our population-based twin cohort revealed that low birth weight increased the risk for development of IBS, with environmental influences in utero as the most relevant contributing factor. We hypothesise that both intrauterine and genetic factors influence the co-occurrence of IBS and symptoms of anxiety and depression.

Methods

A postal questionnaire sent to 12700 Norwegian twins born between 1967 and 1979 comprised a checklist of 31 illnesses and symptoms, including IBS and symptoms of anxiety and depression. The influence of genetic factors and intrauterine growth on comorbidity between these disorders were analysed in the full sample and compared to those based on only monozygotic (MZ) twin pairs discordant for IBS (95 pairs) in birth weight group < 2500 g and ≥ 2500 g.

Results

In the co-twin analyses restricted growth (birth weight < 2500 g) was significantly associated with anxiety and depression (average birth weight difference of 181.0 g (p <0.0001) and 249.9 g (p < 0.0001), respectively).

The analysis of the full sample revealed that IBS was significantly associated with symptoms of anxiety (adjusted OR = 2.5, 95% CI: 1.9, 3.3) and depression (adjusted OR = 2.3. 95% CI: 1.8, 3.0). Analyses of MZ pairs discordant for IBS indicated significant associations between IBS and symptoms of anxiety (OR = 3.7, 95% CI: 1.3, 10.5) and between IBS and symptoms of depression (OR = 4.2, 95% CI: 1.7, 9.9) only in the birth weight group below 2500 g.

Conclusion

Our findings suggest that genetic factors partly explain the association between IBS and symptoms of anxiety and depression. In the low range of birth weight (<2500 g), restricted fetal growth seems to be a common contributing factor to the co-occurrence between these disorders.

Reduced expression of aquaporins in human intestinal mucosa in early stage inflammatory bowel disease

Objectives

The aim of this study was to investigate the relationship between aquaporin (AQP) water channel expression and the pathological features of early untreated inflammatory bowel disease (IBD) in humans.

Methods

Patients suspected to have IBD on the basis of predefined symptoms, including abdominal pain, diarrhea, and/or blood in stool for more than 10 days, were examined at the local hospital. Colonoscopy with biopsies was performed and blood samples were taken. Patients who did not meet the diagnostic criteria for IBD and who displayed no evidence of infection or other pathology in the gut were included as symptomatic non-IBD controls. AQP1, 3, 4, 5, 7, 8, and 9 messenger RNA (mRNA) levels were quantified in biopsies from the distal ileum and colon by quantitative real-time polymerase chain reaction. Protein expression of selected AQPs was assessed by confocal microscopy. Through multiple alignments of the deduced amino acid sequences, the putative three-dimensional structures of AQP1, 3, 7, and 8 were modeled.

Results

AQP1, 3, 7, and 8 mRNAs were detected in all parts of the intestinal mucosa. Notably, AQP1 and AQP3 mRNA levels were reduced in the ileum of patients with Crohn’s disease, and AQP7 and AQP8 mRNA levels were reduced in the ileum and the colon of patients with ulcerative colitis. Immunofluorescence confocal microscopy showed localization of AQP3, 7, and 8 at the mucosal epithelium, whereas the expression of AQP1 was mainly confined to the endothelial cells and erythrocytes. The reduction in the level of AQP3, 7, and 8 mRNA was confirmed by immunofluorescence, which also indicated a reduction of apical immunolabeling for AQP8 in the colonic surface epithelium and crypts of the IBD samples. This could indicate loss of epithelial polarity in IBD, leading to disrupted barrier function.

Conclusion

AQPs 1 and 8 and the aquaglyceroporins AQPs 3 and 7 are the AQPs predominantly expressed in the lower intestinal tract of humans. Their expression is significantly reduced in patients with IBD, and they are differentially expressed in specific bowel segments in patients with Crohn’s disease and ulcerative colitis. The data present a link between gut inflammation and water/solute homeostasis, suggesting that AQPs may play a significant role in IBD pathophysiology.

Early anti-TNF treatment in pediatric Crohn's disease. Predictors of clinical outcome in a population-based cohort of newly diagnosed patients

OBJECTIVE

Pediatric Crohn's disease (CD) is often debilitating, with upper gastrointestinal (GI) involvement and complications over time. Treatment with tumor necrosis factor (TNF) blockers can induce and maintain remission. We wanted to evaluate the outcome of patients medically treated for CD to investigate whether clinical, endoscopic and biochemical factors at diagnosis are associated with the early initiation of treatment with the TNF blocker infliximab.

MATERIALS AND METHODS

Patients aged <18 years, diagnosed with CD were characterized according to the Porto criteria, with endoscopy, magnetic resonance imaging and biochemical tests before individual treatment. They were followed prospectively until a prescheduled examination within 2 years.

RESULTS

Thirty-six pediatric patients were included, 18 (50%) received infliximab. Infliximab-treated patients had shorter disease duration, more upper GI involvement (p = 0.03) and higher median C-reactive protein (CRP) (28 vs. 7.5 mg/l, p = 0.02), erythrocyte sedimentation rate (ESR) (32 vs. 18 mm/h, p = 0.01) and fecal calprotectin (1506 vs. 501 mg/kg, p = 0.01) levels. Infliximab treatment was well tolerated, and 15/18 of patients achieved clinical remission. At follow-up, 11/17 in the infliximab group and 8/13 in the non-infliximab group achieved ileocolonic mucosal healing. A majority in the infliximab group had a marked reduction of CD-specific upper GI lesions but persistence of unspecific upper GI inflammation at follow-up.

CONCLUSION

High levels of inflammatory markers and upper GI lesions were associated with initiation of infliximab treatment. A substantial proportion of patients still had unspecific lesions in the upper GI tract regardless of treatment. Future studies must clarify the prognostic role of persistent upper GI-involvement despite mucosal healing in the ileocolon.

TCF-1-mediated Wnt signaling regulates Paneth cell innate immune defense effectors HD-5 and -6: implications for Crohn's disease

Wnt signaling regulates small intestinal stem cell maintenance and Paneth cell differentiation. In patients with ileal Crohn's disease (CD), a decrease of Paneth cell α-defensins has been observed that is partially caused by impaired TCF-4 and LRP6 function. Here we show reduced expression of the Wnt signaling effector TCF-1 (also known as TCF-7) in patients with ileal CD. Reporter gene assays and in vitro promoter binding analysis revealed that TCF-1 activates α-defensin HD-5 and HD-6 transcription in cooperation with β-catenin and that activation is mediated by three distinct TCF binding sites. EMSA analysis showed binding of TCF-1 to the respective motifs. In ileal CD patients, TCF-1 mRNA expression levels were significantly reduced. Moreover, we found specifically reduced expression of active TCF-1 mRNA isoforms. Tcf-1 knockout mice exhibited reduced cryptdin expression in the jejunum, which was not consistently seen at other small intestinal locations. Our data provide evidence that TCF-1-mediated Wnt signaling is disturbed in small intestinal CD, which might contribute to the observed barrier dysfunction in the disease.

Risk matrix for prediction of advanced disease in a population-based study of patients with Crohn's Disease (the IBSEN Study)

BACKGROUND

Identifying patients with Crohn's disease with increased risk of subsequent complications is essential for appropriate treatment. Based on exploratory analysis, we developed a prediction model for assessing the probability of developing advanced disease 5 and 10 years after diagnosis.

METHODS

A population-based cohort of 237 patients with Crohn's disease diagnosed from 1990-1994 was followed for 10 years. In the 5-year analysis, advanced disease was defined as having intestinal resection, progression in disease behavior, or need for thiopurines. The analysis was limited to patients with uncomplicated disease at diagnosis who were alive (n = 140), excluding those who were lost during follow-up (n = 8). For the 10-year analysis, advanced disease was defined as having surgery, excluding those who had surgery within the first 30 days (n = 7), those who died (n = 18), or were lost during follow-up (n = 22). Based on the best fitted multiple model, the probabilities of advanced disease were computed for selected baseline levels of the covariates and the results were arranged in a prediction matrix. Except for ASCA, all predictors were measured at diagnosis.

RESULTS

ASCA status, disease location, age, and need for systemic steroids were included in the 5-year prediction matrix. The probabilities of advanced disease during this period varied from 8.6% to 92.0% depending on the combination of predictors. The 10-year matrix combined ASCA status, disease behavior, age, and need for systemic steroids; the probabilities of advanced disease ranged from 12.4% to 96.7%.

CONCLUSIONS

Our prediction models revealed substantial differences in the probability of developing advanced disease in the short and intermediate course of Crohn's disease, suggesting that a model-based prediction matrix is useful in early disease management.

Association between variants of PRDM1 and NDP52 and Crohn's disease, based on exome sequencing and functional studies

BACKGROUND & AIMS

Genome-wide association studies (GWAS) have identified 140 Crohn's disease (CD) susceptibility loci. For most loci, the variants that cause disease are not known and the genes affected by these variants have not been identified. We aimed to identify variants that cause CD through detailed sequencing, genetic association, expression, and functional studies.

METHODS

We sequenced whole exomes of 42 unrelated subjects with CD and 5 healthy subjects (controls) and then filtered single nucleotide variants by incorporating association results from meta-analyses of CD GWAS and in silico mutation effect prediction algorithms. We then genotyped 9348 subjects with CD, 2868 subjects with ulcerative colitis, and 14,567 control subjects and associated variants analyzed in functional studies using materials from subjects and controls and in vitro model systems.

RESULTS

We identified rare missense mutations in PR domain-containing 1 (PRDM1) and associated these with CD. These mutations increased proliferation of T cells and secretion of cytokines on activation and increased expression of the adhesion molecule L-selectin. A common CD risk allele, identified in GWAS, correlated with reduced expression of PRDM1 in ileal biopsy specimens and peripheral blood mononuclear cells (combined P = 1.6 × 10(-8)). We identified an association between CD and a common missense variant, Val248Ala, in nuclear domain 10 protein 52 (NDP52) (P = 4.83 × 10(-9)). We found that this variant impairs the regulatory functions of NDP52 to inhibit nuclear factor κB activation of genes that regulate inflammation and affect the stability of proteins in Toll-like receptor pathways.

CONCLUSIONS

We have extended the results of GWAS and provide evidence that variants in PRDM1 and NDP52 determine susceptibility to CD. PRDM1 maps adjacent to a CD interval identified in GWAS and encodes a transcription factor expressed by T and B cells. NDP52 is an adaptor protein that functions in selective autophagy of intracellular bacteria and signaling molecules, supporting the role of autophagy in the pathogenesis of CD.

Dense genotyping of immune-related disease regions identifies nine new risk loci for primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a severe liver disease of unknown etiology leading to fibrotic destruction of the bile ducts and ultimately to the need for liver transplantation. We compared 3,789 PSC cases of European ancestry to 25,079 population controls across 130,422 SNPs genotyped using the Immunochip. We identified 12 genome-wide significant associations outside the human leukocyte antigen (HLA) complex, 9 of which were new, increasing the number of known PSC risk loci to 16. Despite comorbidity with inflammatory bowel disease (IBD) in 72% of the cases, 6 of the 12 loci showed significantly stronger association with PSC than with IBD, suggesting overlapping yet distinct genetic architectures for these two diseases. We incorporated association statistics from 7 diseases clinically occurring with PSC in the analysis and found suggestive evidence for 33 additional pleiotropic PSC risk loci. Together with network analyses, these findings add to the genetic risk map of PSC and expand on the relationship between PSC and other immune-mediated diseases.

Can temperature explain the latitudinal gradient of ulcerative colitis? Cohort of Norway

Background

Incidence and prevalence of ulcerative colitis follow a north–south (latitudinal) gradient and increases northwards at the northern hemisphere or southwards at the southern hemisphere. The disease has increased during the last decades. The temporal trend has been explained by the hygiene hypothesis, but few parallel explanations exist for the spatial variability. Many factors are linked to latitude such as climate. Our purpose was to investigate the association between variables governing the climate and prospectively identified patients.

Methods

In this study, we used a subset of the population-based Cohort of Norway (n = 80412) where 370 prevalent cases of ulcerative colitis were identified through self-reported medication. The meteorological and climatic variables temperature, precipitation, and altitude were recorded from weather stations of the Norwegian Meteorological Institute. Summer temperature was used to capture environmental temperature.

Results

Summer temperature was significantly related to the prevalence of ulcerative colitis. For each one-degree increase in temperature the odds for ulcerative colitis decreased with about 9% (95% CI: 3%-15%). None of the other climatic factors were significantly associated to the risk of ulcerative colitis. Contextual variables did not change the association to the prevalence of ulcerative colitis.

Conclusions

The present results show that the prevalence of ulcerative colitis is associated to summer temperature. Our speculation is that summer temperature works as an instrumental variable for the effect of microbial species richness on the development of ulcerative colitis. Environmental temperature is one of the main forces governing microbial species richness and the microbial composition of the commensal gut flora is known to be an important part in the process leading to ulcerative colitis.

The distribution of chromosomal and microsatellite instability in colorectal cancers related to inflammatory bowel disease

3607

Background: Surveillance for colorectal cancer (CRC) in inflammatory bowel disease (IBD) has so far not been effective. Mucosal or fecal biomarkers may be useful in the selection of high risk patients. The yield may depend on the underlying carcinogenic pathway. In IBD associated CRC (IBD-CRC) the distribution of chromosomal instability (CIN) and microsatellite instability (MSI) is not well documented. Our objective was to determine the distribution of CIN and MSI and the association to clinico-histological factors in a cohort of patients with IBD-CRC. Methods: Ploidy was measured by high-resolution image cytometry and MSI by using two markers (BAT 25 and BAT26) in 62 patients with 72 CRC-IBD selected by matching the Norwegian Cancer Registry with IBD cohorts of three university hospitals in Oslo. The association between ploidy/MSI status and clinicohistological factors were analyzed by non-parametric tests. Results: Ploidy status was analyzed in 67 (93%), microsatellite stability in 68 (94%) tumors. Fourty-nine (73.1%) were non-diploid (43 aneuploid, 1 polyploid, 5 tetraploid), 13 (19.4 %) diploid, five (7.5%) indeterminate. Forty-three (63.2%) were microsatellite stable (MSS), four (5.8%) microsatellite instable (MSI). One tumor was MSI in BAT25 but MSS in BAT26. Twenty (29.5%) tumors showed no PCR-product in at least one of the markers. In 46 tumors, both ploidy and MSI status were available. All non-diploid tumours (36, 78.3%) were MSS and all MSI tumors (4, 8.7%) were diploid. Six (13%) tumors were diploid and MSS. Four patients were treated with 5-ASA prior to diagnosis of CRC. Three developed diploid, one aneuploid cancers. Of the untreated patients, 31 developed aneuploid, 7 diploid cancers (p=0.036). We did not find an association between age, gender, type of IBD, duration of IBD, localisation of CRC,TNM-stage and CIN or MSI. Conclusions: The majority of CRC-IBD in our cohort seem to present CIN and only a minority MSI. Some CRC-IBD patients present neither CIN nor MSI. Future studies should determine whether these display the CpG island methylator phenotype. Biomarkers for CRC-IBD should be derived from all three pathways.

Immunosuppression after liver transplantation for primary sclerosing cholangitis influences activity of inflammatory bowel disease

BACKGROUND & AIMS

Previous studies have shown conflicting results regarding the course of inflammatory bowel disease (IBD) after liver transplantation in patients with primary sclerosing cholangitis (PSC). We studied the progression of IBD in patients with PSC who have undergone liver transplantation. We also studied risk factors, including medical therapy, that could influence on IBD disease activity.

METHODS

In a longitudinal multicenter study, we analyzed data from the Nordic Liver Transplant Group on 439 patients with PSC who underwent liver transplantation from November 1984 through December 2006; 353 had IBD at the time of transplantation. We compared IBD activity before and after liver transplantation. Two hundred eighteen patients who had an intact colon and had undergone pretransplant and post-transplant colonoscopies were characterized further.

RESULTS

Macroscopic colonic inflammation was more frequent after liver transplantation than before liver transplantation (153 vs 124 patients; P < .001). The degree of inflammation decreased in 37 patients (17%), was unchanged in 93 patients (43%), and increased in 88 patients (40%) (P < .001). The rate of relapse after transplantation was higher than that before transplantation (P < .001), and overall clinical IBD activity also increased (P < .001). Young age at diagnosis of IBD and dual treatment with tacrolimus and mycophenolate mofetil were significant risk factors for increased IBD activity after transplantation, whereas combination treatment with cyclosporin A and azathioprine had protective effects.

CONCLUSIONS

Immunosuppression affects IBD activity after liver transplantation in patients with PSC; a shift from present standard maintenance treatment of tacrolimus and mycophenolate mofetil to cyclosporin A and azathioprine should be considered for these patients.

Age-dependent fecal bacterial correlation to inflammatory bowel disease for newly diagnosed untreated children

The knowledge about correlation patterns between the fecal microbiota and inflammatory bowel diseases (IBD)-comprising the two subforms Crohn's disease (CD) and ulcerative colitis (UC)-for newly diagnosed untreated children is limited. To address this knowledge gap, a selection of faecal specimens (CD, n = 27 and UC, n = 16) and non-IBD controls (n = 30) children (age < 18 years) was analysed utilising bacterial small subunit (SSU) rRNA. We found, surprising age dependence for the fecal microbiota correlating to IBD. The most pronounced patterns were that E. coli was positively (R (2) = 0.16, P = 0.05) and Bacteroidetes, negatively (R (2) = 0.15, P = 0.05) correlated to age for CD patients. For UC, we found an apparent opposite age-related disease correlation for both Bacteroides and Escherichia. In addition, there was an overrepresentation of Haemophilus for the UC children. From our, results we propose a model where the aetiology of IBD is related to an on-going immunological development in children requiring different age-dependent bacterial stimuli. The impact of our findings could be a better age stratification for understanding and treating IBD in children.

Geographical variability and environmental risk factors in inflammatory bowel disease

The changing epidemiology of inflammatory bowel disease (IBD) across time and geography suggests that environmental factors play a major role in modifying disease expression. Disease emergence in developing nations suggests that epidemiological evolution is related to westernisation of lifestyle and industrialisation. The strongest environmental associations identified are cigarette smoking and appendectomy, although neither alone explains the variation in incidence of IBD worldwide. Urbanisation of societies, associated with changes in diet, antibiotic use, hygiene status, microbial exposures and pollution have been implicated as potential environmental risk factors for IBD. Changes in socioeconomic status might occur differently in different geographical areas and populations and, consequently, it is important to consider the heterogeneity of risk factors applicable to the individual patient. Environmental risk factors of individual, familial, community-based, country-based and regionally based origin may all contribute to the pathogenesis of IBD. The geographical variation of IBD provides clues for researchers to investigate possible environmental aetiological factors. The present review aims to provide an update of the literature exploring geographical variability in IBD and to explore the environmental risk factors that may account for this variability.

Geographical variability and environmental risk factors in inflammatory bowel disease

The changing epidemiology of inflammatory bowel disease (IBD) across time and geography suggests that environmental factors play a major role in modifying disease expression. Disease emergence in developing nations suggests that epidemiological evolution is related to westernisation of lifestyle and industrialisation. The strongest environmental associations identified are cigarette smoking and appendectomy, although neither alone explains the variation in incidence of IBD worldwide. Urbanisation of societies, associated with changes in diet, antibiotic use, hygiene status, microbial exposures and pollution have been implicated as potential environmental risk factors for IBD. Changes in socioeconomic status might occur differently in different geographical areas and populations and, consequently, it is important to consider the heterogeneity of risk factors applicable to the individual patient. Environmental risk factors of individual, familial, community-based, country-based and regionally based origin may all contribute to the pathogenesis of IBD. The geographical variation of IBD provides clues for researchers to investigate possible environmental aetiological factors. The present review aims to provide an update of the literature exploring geographical variability in IBD and to explore the environmental risk factors that may account for this variability.

Gut bacterial profile in patients newly diagnosed with treatment-naïve Crohn's disease

Objectives:

The aim of this study was to define the composition of the gut bacterial flora in Norwegian patients with early stage Crohn’s disease (CD).

Methods:

By using a nonselective metagenomics approach, the general bacterial composition in mucosal biopsies from the ileum and the colon of five subjects, four patients with different phenotypes of CD, and one noninflammatory bowel disease control, was characterized. After partial 16S ribosomal RNA (rRNA) gene sequencing, BLAST homology searches for species identification and phylogenetic analysis were performed.

Results:

An overall biodiversity of 106 different bacterial operational taxonomic units (OTUs) was detected in the cloned libraries. Nearly all OTUs belonged to the phylae Bacteroidetes (42% in CD, 71% in the control) or Firmicutes (42% in CD, 28% in the control), except for some OTUs that belonged to the phylum Proteobacteria (15% in CD, 0% in the control) and a few OTUs that could not be assigned to a phylum (2% in CD, 1% in the control).

Conclusion:

Based on the high incidence of inflammatory bowel disease (IBD) in Norway, this pilot study represents a relevant determination of the gut microbiota in Norwegian patients compared to previous findings in other countries. The bacterial profile of Norwegian CD patients was found to be similar to that of CD patients in other countries. The findings do not support a particular bacterial composition as a predominant causative factor for the high incidence of IBD that exists in some countries.

Colorectal neoplasia in patients with primary sclerosing cholangitis undergoing liver transplantation: a Nordic multicenter study

OBJECTIVE

Several studies have implicated primary sclerosing cholangitis (PSC) as an additional risk factor for colorectal neoplasia in inflammatory bowel disease (IBD). Some reports have indicated that the risk is even higher in PSC-IBD patients after liver transplantation (Ltx), but this issue is controversial. We aimed to compare the risk of colorectal neoplasia in PSC-IBD patients before and after Ltx and to identify risk factors for colorectal neoplasia post-transplant.

MATERIAL AND METHODS

In a multicenter study within the Nordic Liver Transplant Group, we assessed the risk of colorectal neoplasia by using the competing risk regression analysis.

RESULTS

Among the 439 PSC patients included, 353 (80%) had IBD at the time of Ltx and 15 (3%) patients developed de novo IBD post-Ltx. The median duration of IBD was 15 (0-50) years at the time of Ltx and follow-up after Ltx was 5 (0-20) years. Ninety-one (25%) PSC-IBD patients developed colorectal neoplasia. The cumulative risk of colorectal neoplasia was higher after than before Ltx (HR: 1.9, 95% CI: 1.3-2.9, p = 0.002). A multivariate analysis demonstrated aminosalicylates and ursodeoxycholic acid as significantly associated with an increased risk of colorectal neoplasia post-Ltx. Duration and activity of IBD did not significantly affect the risk of neoplasia.

CONCLUSION

The even higher risk of colorectal neoplasia in PSC-IBD patients after when compared with that of before Ltx underscores the importance of regular surveillance colonoscopies post-Ltx. The association of aminosalicylates and ursodeoxycholic acid to the development of colorectal neoplasia after Ltx should be further investigated.

Health-related quality of life in patients with ulcerative colitis after a 10-year disease course: results from the IBSEN study

BACKGROUND

Ulcerative colitis (UC) negatively affects health-related quality of life (HRQoL), but population-based and long-term data on this topic are scarce. Our aim was to determine the HRQoL in UC patients after a 10-year disease duration.

METHODS

UC patients from a population-based inception cohort met at a prescheduled 10-year follow-up visit. In addition to a clinical examination, interview, and blood samples, the patients completed the Short Form 36 (SF-36) and the Norwegian Inflammatory Bowel Disease Questionnaire (N-IBDQ). The SF-36 scores were compared to scores from a general population sample using one-sample t-tests. Standardized scores were calculated and interpreted according to Cohen's effect size index. The associations between relevant clinical and demographic factors and HRQoL were examined through linear regression analyses.

RESULTS

A total of 196 patients completed the HRQoL questionnaires (response rate: 80%), of whom 54% were women; the mean age of all patients was 48 years (range: 22-86). The SF-36 scores were comparable to those of the general population except for lower scores in the General Health dimension. The SF-36 scores were significantly lower in the presence of current symptoms, in patients who had used corticosteroids, and in patients who reported not working. Overall N-IBDQ scores were equivalent to scores of patients in remission. Female gender, work status (not working), current symptoms, and smoking were associated with significantly lower N-IBDQ scores.

CONCLUSIONS

SF-36 scores were not reduced compared to the general population sample. The presence of current symptoms, the use of corticosteroids, work status (not working), female gender, and smoking had a negative impact on HRQoL.

Inflammatory bowel disease in patients with primary sclerosing cholangitis: clinical characterization in liver transplanted and nontransplanted patients

BACKGROUND

Inflammatory bowel disease (IBD) in patients with primary sclerosing cholangitis (PSC) seems to differ from IBD without PSC, but a systematic, prospective study of IBD in PSC has until now not been reported. We aimed to describe the clinical, endoscopic, and histopathologic features of PSC-IBD in liver-transplanted and nontransplanted patients.

METHODS

PSC patients (n = 184) were included and underwent ileocolonoscopy with assessment of segmental histopathology.

RESULTS

A total of 155 (84%) patients had IBD, of whom 39 (25%) had undergone colectomy. The patients with an intact colon and complete tissue samples (n = 110) were further investigated. Forty-two (38%) patients had undergone liver transplantation. The median IBD duration was 11 (range, 0-50) years. The majority (65%) had no or sparse IBD symptoms. Inflammatory findings were more frequent by histology than by endoscopy (89% versus 47%, P < 0.001). Histopathological signs of inflammation involved the right colon in 86% of patients and were purely right-sided in 23%. The findings of inflammation were higher in the right compared to the left colon (P < 0.001), but the general inflammatory activity was low. Backwash ileitis was demonstrated in 20% (17/87) of patients and rectal sparing in 65% (70/107). The liver-transplanted patients had lower clinical (P = 0.035) and histological (P = 0.013) IBD activity than the nontransplanted group.

CONCLUSIONS

PSC-IBD may represent a distinct entity of colitis in which low endoscopic activity may mask an active histologic inflammation that possibly contributes to an increased risk of malignancy. Circumstances related to liver transplantation seem to act favorably on colonic inflammation in PSC.

Evaluation of disease activity in IBD at the time of diagnosis by the use of clinical, biochemical, and fecal markers

OBJECTIVE

The present population based adult cohort was part of a new prospective study of patients with inflammatory bowel disease (IBD) in South-Eastern Norway, the Inflammatory Bowel South-Eastern Norway II study, investigating disease characteristics in an attempt to improve our knowledge regarding factors related to early clinical phenotype and disease activity.

MATERIAL AND METHODS

Patients suspected to have IBD on the basis of predefined symptoms, including abdominal pain, diarrhea, and/or blood in stool for more than 10 days were examined at the local hospital. Colonoscopy with biopsies was performed and blood and stool samples were taken.

RESULTS

In ulcerative colitis (UC) patients, the median Simple Clinical Colitis Activity Index (SCCAI) was 4 (range 0-10) in mild and 6 (range 0-14) in patients with moderate or severe endoscopic activity of inflammation (p = 0.002). The calprotectin concentration in feces was significantly related to the SCCAI (p = 0.034) and the Mayo endoscopic subscore (p = 0.031). There was a significant association between the C-reactive protein (CRP) value, leucocytes and thrombocytes and the SCCAI, but only leucocytes were significantly associated with the Mayo endoscopic subscore. In Crohn's disease (CD) patients, there was no statistical significant association between the Harvey-Bradshaw Index (HBI) and the endoscopic grade of mucosal inflammation (p = 0.8). The calprotectin concentration in feces was significantly related to the endoscopic activity score (p = 0.004), but not to the HBI (p = 0.5). HBI was significantly related to the CRP value (p = 0.047) and thrombocytes (p = 0.03).

CONCLUSIONS

In UC, both biochemical and fecal markers are related to disease activity and extent of disease, whereas in CD, the fecal calprotectin concentration is a reliable marker of mucosal affection, but not for systemic disease activity.

IBD Around the world: comparing the epidemiology, diagnosis, and treatment: proceedings of the World Digestive Health Day 2010--Inflammatory Bowel Disease Task Force meeting

Every May 29th the World Gastroenterology Organization (WGO) celebrates World Digestive Health Day (WDHD) and initiates a worldwide public health campaign through its 110 national societies and 50,000 members. Each year focuses on a particular digestive disorder in order to increase general public awareness of prevention and therapy. 2010 is dedicated to inflammatory bowel disease (IBD). Upon this occasion a WGO IBD task force was compiled from leading international specialists and researchers. The task force also included members of the American Gastroenterological Association (AGA), International Organization for the Study of Inflammatory Diseases (IOIBD) and the European Crohn's and Colitis Organization (ECCO) of the United European Gastroenterology Federation (UEGF). The goal of the task force was to bring together IBD specialists from around the world to discuss the epidemiology, diagnosis, and management of IBD within different regions. This is a summary of the WGO task force meeting at the American Gastroenterological Association's (AGA) Digestive Disease Week, held in New Orleans, Louisiana, USA, May, 2010. The expert panel identified the most pressing issues in IBD worldwide: reliable epidemiological data, global collaboration in clinical and basic research, the approach to distinguishing intestinal tuberculosis from Crohn's disease, access to specialist care and access to the latest diagnostic and therapeutic strategies.

DNA sequence profiles of the colorectal cancer critical gene set KRAS-BRAF-PIK3CA-PTEN-TP53 related to age at disease onset

The incidence of colorectal cancer (CRC) increases with age and early onset indicates an increased likelihood for genetic predisposition for this disease. The somatic genetics of tumor development in relation to patient age remains mostly unknown. We have examined the mutation status of five known cancer critical genes in relation to age at diagnosis, and compared the genomic complexity of tumors from young patients without known CRC syndromes with those from elderly patients. Among 181 CRC patients, stratified by microsatellite instability status, DNA sequence changes were identified in KRAS (32%), BRAF (16%), PIK3CA (4%), PTEN (14%) and TP53 (51%). In patients younger than 50 years (n = 45), PIK3CA mutations were not observed and TP53 mutations were more frequent than in the older age groups. The total gene mutation index was lowest in tumors from the youngest patients. In contrast, the genome complexity, assessed as copy number aberrations, was highest in tumors from the youngest patients. A comparable number of tumors from young (<50 years) and old patients (>70 years) was quadruple negative for the four predictive gene markers (KRAS-BRAF-PIK3CA-PTEN); however, 16% of young versus only 1% of the old patients had tumor mutations in PTEN/PIK3CA exclusively. This implies that mutation testing for prediction of EGFR treatment response may be restricted to KRAS and BRAF in elderly (>70 years) patients. Distinct genetic differences found in tumors from young and elderly patients, whom are comparable for known clinical and pathological variables, indicate that young patients have a different genetic risk profile for CRC development than older patients.

Paucity of mycobacteria in mucosal bowel biopsies from adults and children with early inflammatory bowel disease

BACKGROUND

The presence of Mycobacterium avium subspecies paratuberculosis (MAP) has previously been inferred in the genesis of Crohn's disease (CD), and a higher incidence of MAP PCR positivity has been demonstrated in the gut and peripheral blood of CD patients than in healthy individuals. The objective of this prospective study was to assess the potential etiological role of MAP in the pathogenesis of CD.

METHODS

The presence of mycobacteria was assessed in bowel biopsies from newly diagnosed, treatment naïve Norwegian patients with IBD, including CD and ulcerative colitis (UC), as compared to a hospital-based cohort of CD and UC patients. Biopsies were collected from the small and large bowel in 354 individuals with suspected IBD. Detection of mycobacteria was performed by long-term cultivation in combination with direct detection by MAP IS900-specific PCR.

RESULTS

Among the specimens included from the patients with early IBD, samples from only two of the patients with CD (2.7%) and two of the non-IBD controls (1.5%) exhibited a positive growth signal. None of the CD patients and only one of the non-IBD controls was MAP PCR positive. Only the single PCR positive non-IBD control was also mycobacterial culture positive with Mycobacterium avium subsp. hominissuis. In the referral patients with long-term IBD, the prevalence of growth signal and MAP PCR positivity was higher (52 and 9%, respectively).

CONCLUSIONS

These findings demonstrate the paucity of MAP in the gut of treatment naïve CD patients. This study does not provide evidence for a role of MAP in early IBD.

Inflammatory bowel disease-associated interleukin-33 is preferentially expressed in ulceration-associated myofibroblasts

Interleukin-33 (IL-33) is a novel member of the interleukin-1 family that induces mucosal pathology in vivo and may drive fibrosis development and angiogenesis. To address its potential role in inflammatory bowel disease, we explored its tissue expression in biopsy specimens from untreated ulcerative colitis patients, observing a 2.6-fold up-regulation of IL-33 mRNA levels, compared to controls. Immunohistochemical analyses of surgical specimens showed that a prominent source of IL-33 in ulcerative colitis lesions were ulceration-associated myofibroblasts that co-expressed the fibroblast marker heat shock protein 47, platelet-derived growth factor receptor (PDGFR)β, and, in part, the myofibroblast marker α-smooth muscle actin (SMA). In contrast, IL-33-positive myofibroblasts were almost absent near the deep fissures seen in Crohn's disease. A screen of known and putative activators of IL-33 in cultured fibroblasts revealed that the Toll-like receptor-3 agonist poly (I:C) was among the strongest inducers of IL-33 and that it synergized with transforming growth factor-β, a combination also known to boost myofibroblast differentiation. Experimental wound healing in rat skin revealed that the de novo induction of IL-33 in pericytes and the possible activation of scattered, tissue-resident IL-33(+)PDGFRβ(+)αSMA(-) fibroblast-like cells were early events that preceded the later appearance of IL-33(+)PDGFRβ(+)αSMA(+) cells. In conclusion, our data point to a novel role for IL-33 in mucosal healing and wound repair and to an interesting difference between ulcerative colitis and Crohn's disease.

Concordance for IBD among twins compared to ordinary siblings--a Norwegian population-based study

AIMS

Comparing the risk to develop concordant disease among twins with inflammatory bowel disease (IBD) to ordinary siblings. Moreover, clinical characteristics of IBD and the association between perinatal factors and IBD, were evaluated.

METHODS

Patients with IBD, enrolled from an incidence study between 1990 and 1994, and the twins were identified from the Norwegian national birth registry, which was established in 1967.

RESULTS

Eight monozygotic and 16 dizygotic pairs, in which at least one twin reported a positive history of IBD were compared to 84 patients with Crohn's disease (CD) and 87 patients with ulcerative colitis (UC) from the incidence study. The relative risks for concordant disease in monozygotic pairs were estimated to 95.4 (95% CI: 76.3, 114.6) and 49.5 (95% CI: 35.7, 63.3) for CD and UC, respectively. The corresponding risks in dizygotic pairs were 42.4 (95% CI: 29.6, 55.2) and 0.0. Among ordinary siblings of CD and UC the risks for concordance were 22.7 (95% CI: 13.3, 32.1) and 4.6 (95% CI: 0.4, 8.7), respectively. Stricturing disease was significantly higher in twins with CD compared to incidental cases. The first-born twin in pairs discordant for disease, 12 out of 19 (63.2%), tended to be affected by IBD (p=0.10).

CONCLUSION

Genetic factors influence the development of IBD and fibrostenotic disease in CD. The increased risk for concordant disease among dizygotic twins compared to ordinary siblings, at least in CD, might underscore the importance of shared environment in utero or in childhood.

Mutational characterization of the bile acid receptor TGR5 in primary sclerosing cholangitis

Background

TGR5, the G protein-coupled bile acid receptor 1 (GPBAR1), has been linked to inflammatory pathways as well as bile homeostasis, and could therefore be involved in primary sclerosing cholangitis (PSC) a chronic inflammatory bile duct disease. We aimed to extensively investigate TGR5 sequence variation in PSC, as well as functionally characterize detected variants.

Methodology/Principal Findings

Complete resequencing of TGR5 was performed in 267 PSC patients and 274 healthy controls. Six nonsynonymous mutations were identified in addition to 16 other novel single-nucleotide polymorphisms. To investigate the impact from the nonsynonymous variants on TGR5, we created a receptor model, and introduced mutated TGR5 constructs into human epithelial cell lines. By using confocal microscopy, flow cytometry and a cAMP-sensitive luciferase assay, five of the nonsynonymous mutations (W83R, V178M, A217P, S272G and Q296X) were found to reduce or abolish TGR5 function. Fine-mapping of the previously reported PSC and UC associated locus at chromosome 2q35 in large patient panels revealed an overall association between the TGR5 single-nucleotide polymorphism rs11554825 and PSC (odds ratio  = 1.14, 95% confidence interval: 1.03–1.26, p = 0.010) and UC (odds ratio  = 1.19, 95% confidence interval 1.11–1.27, p = 8.5×10⁻⁷), but strong linkage disequilibrium precluded demarcation of TGR5 from neighboring genes.

Conclusions/Significance

Resequencing of TGR5 along with functional investigations of novel variants provided unique insight into an important candidate gene for several inflammatory and metabolic conditions. While significant TGR5 associations were detected in both UC and PSC, further studies are needed to conclusively define the role of TGR5 variation in these diseases.

Relationships between inflammatory bowel disease and perinatal factors: both maternal and paternal disease are related to preterm birth of offspring

BACKGROUND

The aims of this study were to explore the influences of familial, maternal, and paternal inflammatory disease (IBD) on perinatal outcomes in the offspring and the risk for development of IBD related to perinatal factors.

METHODS

Eighty-five patients with Crohn's disease (CD) and 86 with ulcerative colitis (UC) were included from a population-based incidence study enrolled 1990-1994. Family and birth records of these patients, as well as of their 207 infants, were drawn from the Norwegian Medical Birth Registry, established in 1967, and compared with the national birth cohort from the same period.

RESULTS

Maternal (odds ratio [OR] = 2.15, 95% confidence interval [CI]: 1.36, 3.39) and paternal IBD (OR = 3.02, 95% CI: 1.82, 5.01) influenced the risk of preterm birth (<37 weeks), which further increased if the affected parents had a first-degree relative with IBD (OR = 4.29, 95% CI: 1.59, 11.63). Maternal CD was associated with lower birth weight in the offspring (crude difference: 271.79 g, 95% CI: 87.83, 455.77, versus controls). Maternal UC increased the risk of perinatal bacterial infection in the offspring (OR = 6.03, 95% CI: 2.03, 17.91). IBD patients (2.3%) were less likely to be delivered by cesarean section than controls (8.1%) (OR = 0.27, CI: 95%: 0.10, 0.73).

CONCLUSIONS

Familial, maternal, and paternal IBD were linked to preterm birth, which might be explained by genetic mechanisms. The present protective effect of cesarean sections needs further clarification in future studies.

Widespread but not localized neoplasia in inflammatory bowel disease worsens the prognosis of colorectal cancer

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer (CRC). Recently, new phenotypes of CRC in IBD have been suggested. Studies of the prognosis of CRC in IBD have shown conflicting results. The aim of the study was to analyze factors for prognosis in CRC-IBD, including the impact of the new phenotypes.

METHODS

By using the nationwide, population-based Cancer Registry of Norway, we compared survival of a CRC-IBD cohort with CRC in the background population (all-CRC), adjusting for the topographical distribution of dysplasia at cancer diagnosis (widespread versus localized neoplasia in IBD) and other factors. We also analyzed prognostic factors within CRC-IBD.

RESULTS

The mean age at CRC diagnosis was 43 years in widespread, 52 years in localized neoplasia IBD, and 70 years in all-CRC (P < 0.05). Adjusted for cofactors, prognosis of CRC-IBD was poorer compared to all-CRC (mortality rate ratio [MRR] 3.71, 95% confidence interval [CI]: 2.54-5.42, P < 0.001). Prognosis of widespread neoplasia IBD was poorer compared to all-CRC (MRR 4.27, 95% CI: 2.83-6.44, P < 0.001) and compared to localized neoplasia IBD (MRR 3.58, 95% CI: 0.87-14.72, P = 0.076). Survival was not significantly different between localized neoplasia IBD and all-CRC (P = 0.132).

CONCLUSIONS

The results demonstrate lower age and poorer survival of CRC in IBD compared to CRC in the background population. The unfavorable effect of IBD on prognosis of CRC was pronounced in widespread neoplasia IBD. The diagnosis of this phenotype seems to be an important prognostic sign in patients with CRC in IBD.

Treatment of fulminant ulcerative colitis with cyclosporine A

OBJECTIVE. Fulminant ulcerative colitis not responding to high doses of corticosteroids remains a clinical challenge. Intravenous infusion of cyclosporine A (CyA) has shown an excellent short-term response, but its use has been restricted by potential serious adverse events and reports of high short- and long-term colectomy rates. The purpose of this study was to report on the Oslo experience with CyA in fulminant ulcerative colitis. MATERIAL AND METHODS. Between 1993 and 2006, intravenous CyA (5 mg/kg) was administered to 18 patients with fulminant ulcerative colitis. Responders were discharged under a 6 months' course of oral CyA. Patients were prospectively followed at 2, 6, 12 and 24 months after discharge. RESULTS. Fifteen patients (83%) responded to intravenous CyA treatment. On follow-up at 2, 6, 12 and 24 months, the colectomy-free rates were 72%, 67%, 61% and 56%, respectively. After a median follow-up of 60.3 months (range 1.7-146), 8 patients (44%) still had avoided having to undergo a colectomy. All patients had at least one relapse during follow-up. Only one patient had to discontinue CyA owing to adverse events. CONCLUSION. At our institution, CyA treatment of fulminant ulcerative colitis is an effective and safe treatment.

Clustering in time of familial IBD separates ulcerative colitis from Crohn's disease

BACKGROUND

The aim was to compare clustering of time at diagnosis and phenotype of inflammatory bowel disease (IBD) between affected parents and children and to explore generational differences in age at diagnosis (AAD) as well as the concordance of clinical characteristics.

METHODS

Eighty-four affected pairs from 45 families were included from 5 counties in southeastern Norway between August 2003 and December 2006; 43 were sib-sib pairs and 39 parent-child pairs. Clinical data were obtained by phone interviews and by hospital records.

RESULTS

The difference in median AAD was 17.0 years (P < 0.001) and 2.0 years (P = 0.29) in parent-child and sib-sib pairs, respectively. When the time interval between diagnosis in parent and child was split into 2 groups, below and above 5 years, 64% of pairs with ulcerative colitis (UC) offspring were diagnosed within 5 years, compared to 24% of pairs with Crohn's disease (CD) offspring (odds ratio [OR] = 5.7, 95% confidence interval [CI]: 1.4, 23.8). Concordance for smoking habits was low in 26 pairs with mixed disease (κ = 0.15), whereas patients with CD tended to be current smokers.

CONCLUSIONS

Most of the children acquire their disease at an earlier time in life compared to their parents, suggesting genetic anticipation. The time interval between diagnosis of the parents and offspring was lower when the offspring developed UC compared to CD, which might reflect the influence of shared environment on the generational difference in AAD in UC families. This study confirmed the effect of smoking habits on IBD phenotype.

Mucosal healing: impact on the natural course or therapeutic strategies

BACKGROUND

The treatment with anti-TNF in inflammatory bowel disease (IBD) has shown a much higher rate of mucosal healing (MH) compared to previous treatments. As MH after treatment also seemed to predict a positive outcome of disease regarding long-term outcome and reduced economic burden on the healthcare system, the question was if MH would have an impact on both the natural course of disease and treatment strategy. AREAS OF EXPERIENCE: Literature search includes population-based cohort studies, such as the Norwegian IBSEN study, and hospital-based studies, such as the GETAID study from France, both referring to MH in prospective follow-up studies of treatment prior to the introduction of biologics. Additionally, experience is based on short- and long-term efficacy studies with anti-TNF treatment, especially infliximab. From all studies, predictability of MH on long-term outcome of disease, including surgery and hospitalization, was assessed.

RESULTS

MH predicts a generally favorable outcome of disease based on all types of treatment strategies, except glucocorticosteroids, and is related to treatment efficacy-reduced frequency of surgery and hospitalizations. Scheduled treatment with anti-TNF is superior to episodic treatment and a top-down strategy has a favorable effect on healing. A limitation of MH as a universal marker is the fact that less than 50% of patients with a clinical effect of treatment acquire complete healing and MH appears in less than 30% of all patients on anti-TNF.

CONCLUSION

MH has become a valuable marker of efficacy in IBD, predicting a favorable disease outcome. In the future, additional markers of healing are expected to be combined with today's endoscopic and histologic assessments.

Increased number and activation of colonic macrophages in pediatric patients with untreated Crohn's disease

BACKGROUND

Pediatric inflammatory bowel disease (IBD) may be phenotypically different from adult IBD. In IBD lesions, macrophages are overactivated, suggesting involvement of innate immunity in the pathogenesis. Here, mucosal macrophages were studied in selected untreated pediatric patients compared with adults from a population-based Norwegian cohort of IBD patients. Age-matched non-IBD controls were also included.

METHODS

Untreated children (<18 years) and adults (> or =18 years) were included at diagnosis with colonic and ileal biopsies. Controls were symptomatic non-IBD patients with histologically normal gut. Frozen mucosal sections were examined by immunohistochemistry for cellular expression of the pan-macrophage marker CD68 and the costimulatory molecule CD40. Two-color immunofluorescence staining in situ was performed to identify CD40(+) macrophages.

RESULTS

Non-IBD adults had significantly higher mucosal density of colonic CD68(+) macrophages than non-IBD children. In pediatric Crohn's disease (CD), macrophages were significantly increased in the colon (but not in the ileum) compared with controls. Their mucosal density in pediatric CD was significantly higher than in pediatric ulcerative colitis. The number of CD40(+) (activated) macrophages was significantly elevated in both histologically inflamed and uninflamed colon and ileum of IBD children.

CONCLUSIONS

Histologically normal colon mucosa contains fewer macrophages in children than in adults. However, in colon of children with untreated CD the mucosal macrophage density is increased. Activated mucosal macrophages are increased in untreated pediatric IBD regardless of inflammatory grade. Such upregulated innate mucosal immune activation may contribute to the colonic phenotype of childhood CD.

A characterization in childhood inflammatory bowel disease, a new population-based inception cohort from South-Eastern Norway, 2005-07, showing increased incidence in Crohn's disease

OBJECTIVE

Owing to rising incidence rates in inflammatory bowel disease (IBD), there has been increased interest in causal relationships in pediatric disease. The present population-based inception cohort was recruited in the Oslo area from 2005 to 2007, with the aim of conducting a detailed characterization of treatment-naive patients at diagnosis.

MATERIAL AND METHODS

After an invitation was extended to all general practitioners in the catchment area, patients aged <18 years with suspected IBD were diagnosed by proximal and distal endoscopy, MRI, demographic, clinical, and histological and molecular characteristics. Symptomatic non-IBD patients served as controls.

RESULTS

Of 100 pediatric patients, 62 had IBD (39 Crohn's disease (CD), 19 ulcerative colitis (UC), 4 IBD unclassified (IBDU)) and 38 other diseases. Median age at diagnosis for IBD was 13.1 years (56.4% males), median symptom duration 6 months, and 69% L3 (Vienna classification). With 195,000 children aged <18 years in the catchment area, the incidence rate of IBD per 100,000/years inhabitants was 10.9 (6.8 for CD, 3.6 for UC, and 0.6 IBDU) and for those aged <16 years (178,500) the incidence rate was 10.6. The higher NOD2 allele frequency among children may partly contribute to the increase.

CONCLUSIONS

The results indicate a marked rise in the incidence of CD in contrast to no increase in UC in South-Eastern Norway, compared with the figures from the last 15 years. Time from onset of symptoms to diagnosis still represents a challenge for early characterization in IBD.

Familial aggregation in Crohn's disease and ulcerative colitis in a Norwegian population-based cohort followed for ten years

BACKGROUND AND AIMS

To explore the change in risk among 1st degree relatives of ulcerative colitis (UC) and Crohn's disease (CD) for development of concordant disease in an incidence cohort followed for ten years. Furthermore, we wanted to compare familial and sporadic cases regarding clinical characteristics and the course of the disease.

METHODS

This population-based study included 421 patients with UC and 197 with CD enrolled from 1990 to 1994. Clinical characteristics and the number of 1st degree relatives of the patients were recorded continuously during ten years.

RESULTS

Age at diagnosis in CD patients (OR=0.95, 95% CI: 0.93-0.98) and cumulative relapse rate in UC patients (OR=4.91, 95% CI=1.16, 20.75) were significantly associated to familial clustering. Based on the calculated population prevalence of CD (262/100000) and UC (505/100000), the age-adjusted risk for development of concordant disease was 25.9 and 8.6 among siblings and parents of CD, respectively. In UC, the corresponding risks were 8.6 and 1.5. In the course of ten years the increase in risk was observed only among siblings (28%) and parents (97%) of UC, in contrast to no increase in CD. Moreover, the concordance for UC was high in three generations.

CONCLUSIONS

Our study confirmed the importance of genetic influence on the development of CD. Within an observation period of ten years, the increased concordance and relapse rate in familial UC, might point to a larger genetic component in UC than previously suggested.

Health related quality of life in patients with neuroendocrine tumors compared with the general Norwegian population

PURPOSE

Health related quality of life (HRQoL) was characterized among patients with neuroendocrine tumor (NET) and compared with the general Norwegian population.

METHODS

A cross sectional, comparative design was chosen, and the samples comprised 196 NET patients and 5,258 individuals from the general Norwegian population. We used Chi-square cross tab calculations to evaluate sociodemographic characteristics, T-tests for independent samples and Analysis of Variance (ANOVA) in order to compare HRQoL (SF-36) scores across a range of background variables. Furthermore, T-tests were used to analyze differences in HRQoL scores between the samples.

RESULTS

NET patients demonstrated significantly lower on all HRQoL subscales when compared with the general population with the lowest values on general health, physical limitation and vitality. Individuals above 70 years reported lower scores on physical functioning and physical limitations compared with those who were younger. Individuals with higher levels of education reported increased physical functioning compared with those with less education and full-time or part-time workers described higher physical functioning and less physical limitations compared with those who were retired.

CONCLUSIONS

All SF-36 HRQoL scores were significantly lower among the NET patients when compared with the general population. Assistance from health personnel to NET patients should focus on those domains.

Extreme heterogeneity in CARD15 and DLG5 Crohn disease-associated polymorphisms between German and Norwegian populations

The first gene associated with Crohn disease (CD) has been identified as CARD15 (16q12). Three variants, R702W, G908R and 1007fsinsC are strongly and independently associated with the disease. A second gene, conveying a smaller risk for inflammatory bowel disease (IBD), has been identified as DLG5 (10q23). We assess the frequency of the CARD15 SNPs and of the R30Q mutation in DLG5 and their contribution to the development of CD in a cohort of unrelated IBD patients (151 CD, 325 ulcerative colitis (UC)) and healthy controls (236) from South-east Norway (IBSEN cohort). Genotype-based tests of population differentiation using 23 SNPs across CARD15, together with estimates of F(ST), indicated that the German and Norwegian background populations could be differentiated at the CARD15 locus. The Norwegian and German CD samples exhibited particularly strong differentiation at the three predisposing loci and those marking their background haplotype. There were significantly lower frequencies of the CARD15 SNPs and no significant association with CD in the Norwegian samples. Only a marginal association was observed for the subphenotypes ileitis and ileocolitis vs colitis (P=0.048). The population attributable risk percentage (PAR%) for CARD15 variants in the Norwegian cohort is the lowest reported for a European population (1.88%), except Iceland. Similarly, the DLG5 variant showed no association with CD or IBD, however, there was a negative correlation with stricture (P=0.035). The present results are consistent with an emerging pattern of a low frequency of the CARD15 variants in Northern countries where the prevalence of IBD is greatest.